Apparatus for forming metal

ABSTRACT

APPARATUS FOR FORMING THE EDGES OF LENGTHS OF SHEET METAL INCLUDING A METAL FORMING MACHINE FOR FORMING THE EDGES OF THE LENGHTS OF SHEET METAL, A FIRST TRANSFER TABLE FOR SUCCESSIVELY MOVING THE LENGTHS OF SHEET METAL ALONG A PRESCRIBED PATH TOWARD THE MACHINE TO A FIRST PREDETERMINED POSITION, A SECOND TRANSFER TABLE FOR SUCCESSIVLEY MOVING THE LENGTHS OF SHEET METAL ALONG THE PRESCRIBED PATH AWAY FROM THE MACHINE AND BACK TOWARD THE MACHINE TO A SECOND PREDETERMINED POSITION, HOLD-DOWN MEANS FOR MAINTAINING THE LENGTHS OF SHEET METAL IN THE FIRST OR SECOND PREDETERMINED POSITIONS, AND TRAVERSING MEANS FOR MOVING THE METAL FORMING MACHINE ACROSS THE PRESCRIBED PATH TO FORM THE LENGTHS OF SHEET METAL IN THE FIRST AN/OR SECOND PREDETERMINED POSITIONS.

0d. 5, 1971 R, HARRls 3,610,017

APPARATUS FOR FQRMiNG METAL Filed April 24, 1969 4 Sheets-Sheet 1 /IVVEN70R P055127 4. 1 /44 215 ,4 r TOR/V5 K5 1971 R. A. HARRIS APPARATUS FORFORMING METAL 4 Sheets-Sheet 2 Filed April 24, 1969 1971 R. A. HARRISAPPARATUS FOR FORMING METAL 4 Sheets-Sheet :5

Filed April 24, 1969 06L 5, 1971 HARRIS 3,610,017

APPARATUS FOR FORMING METAL Filed April 24, 1969 4 Sheets-Sheet 4 C G C5W2 w- 5 7 50L 3 SW-B I U United States Patent US. Cl. 72-307 ClaimsABSTRACT OF THE DISCLOSURE Apparatus for forming the edges of lengths ofsheet metal including a metal forming machine for forming the edges ofthe lengths of sheet metal, a first transfer table for successivelymoving the lengths of sheet metal along a prescribed path toward themachine to a first predetermined position, a second transfer table forsuccessively moving the lengths of sheet metal along the prescribed pathaway from the machine and back toward the machine to a secondpredetermined position, hold-down means for maintaining the lengths ofsheet metal in the first or second predetermined positions, andtraversing means for moving the metal forming machine across theprescribed path to form the lengths of sheet metal in the first and/ orsecond predetermined positions.

BACKGROUND OF THE INVENTION (1) Field of the invention This inventionrelates generally to the forming of metal and more particularly toforming the leading and trailing edges of pieces of metal by holding thepieces of metal stationary while a forming machine is moved across theleading and trailing edges thereof to form the same.

(2) Discussion of the prior art In the past, metal, especially sheetmetal, was first cut to length from a roll and subsequently hand fed toa roll forming machine to form the leading and trailing edges of thesheet metal to form locking grooves and reinforcing angles in the metal.While machines were available on the market to rapidly cut the sheetmetal to lengths, the overall operation of cutting and forming the metalwas very time consuming in that the manually fed forming machines wereslow. Recently, there has been an attempt to manufacture a machine whichwould cut the sheet metal to lengths and subsequently form the same in asingle overall operation without the sheet metal being manually fedthrough the roll forming machine. All of these machines have attemptedto solve this problem by using a complicated transfer system to changethe position of the sheet metal several times and subsequently feed thesheet metal through two separate forming machines either sequentially orsimultaneously to form the locking and reinforcing bends therein. Inthese machines, the forming machine is always stationary and the metalis moved thereby.

SUMARY OF THE INVENTION These and other problems associated with theprior art are overcome by the invention disclosed herein in that metal,especially sheet metal, can be rapidly cut to length and subsequentlyformed in a single overall operation with a minimum of transferequipment and using a single roll forming machine. This not onlysubstantially reduces the initial cost of the equipment, but alsoprovides a fast and efficiently operating machine with a minimum ofmoving parts thereby reducing the overall maintenance cost of themachine.

The method of the invention comprises the steps of moving pieces ofsheet metal successively along a pre scribed path, stopping each pieceof metal at a predeter- Patented Oct. 5, 1971 mined position and movinga metal forming machine across the leading edge thereof, subsequentlymoving the formed piece of metal past the machine, returning the machineto its original position, then moving the formed sheet of metal back toa second predetermined position and moving the next unformed sheet ofmaterial to the first predetermined position, and moving the machineacross the trailing edge of the formed piece of material and the leadingedge of the unformed piece of material to form the same. This operationis repeated on successive pieces of metal.

The apparatus of the invention includes generally an infeed transfertable from moving the pieces of metal to the first predeterminedposition, a metal forming machine mounted on a traversing mechanism tomove the machine back and forth across the path of the pieces of metaland a discharge transfer table for moving the pieces of metal away fromthe forming machine and back toward the forming machine to the secondpredetermined position.

BRIEF DESCRIPTION OF THE DRAWINGS These and other features andadvantages of the invention disclosed herein will become more apparentupon consideration of the following specification and accompanyingdrawings wherein like characters of reference designate correspondingparts throughout the several views and in which:

FIG. 1 is a partial perspective view of one embodiment of the invention;

FIG. 2 is a top plan view of the invention shown in FIG. 1;

FIG. 3 is a shortened side elevational view of the discharge transfertable of the invention shown in FIGS. 1 and 2 with parts thereof brokenaway to show the internal construction thereof;

FIG. 4 is a partial view showing the drive mechanism for the dischargetable;

FIG. 5 is a partial sectional view showing the braking mechanism of themachine;

FIG. 6 is an electrical schematic diagram of the control circuit of theinvention; and,

FIG. 7 is a schematic diagram of the fluid control circuit of theinvention.

These figures and the following detailed description disclose specificembodiments of the invention; however, the inventive concept is notlimited thereto since it may be embodied in other forms.

DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS Referring to FIG. 1, it will beseen that the invention includes generally an infeed transfer table 10,a discharge transfer table 11, a metal forming assembly 12, and atraversing mechanism 14. The infeed transfer table 10 and the dischargetransfer table 11 are aligned so that they will move pieces of metal,here shown as sheet metal M, along a common prescribed path P shown inFIG. 1. The traversing mechanism 14 mounts the metal forming assembly 12and is sufficient to move the metal forming assembly back and forthacross the path P. For sake of clarity, the machine will be divided upinto the components above listed with sub-headings.

Traversing mechanism The traversing mechanism 14 includes a frame 15defined by parallel side members 16 and end members 18. Each side member16 mounts a carriage rail 19 thereon, the carriage rails 19 beinginverted V-shaped members positioned parallel to each other whilesubstantially perpendicular to the path P and spaced there below. Therails 19 serve to guide the assembly 12 properly for forming the metal.A starting fluid cylinder 20 is mounted on one of the end members 18(the near side of the machine as seen in FIG. 1) and has as its pistonrod 21 selectively extendable toward the path P. A pusher plate 22 isprovided on the end of piston rod 21 to start the metal forming assembly12 moving toward the path P as will be explained hereinafter. A returnfluid cylinder 24 is mounted on the end member 18 opposite the startingfluid cylinder 20 and has-its piston rod 25 extending toward the path P.A pusher plate 26 is provided on the extending end of piston rod 25 toreturn the metal forming assembly back across path P, to its initialposition. Each end member 18 pivotally mounts a pair of braking members28 as seen in FIGS. 1 and with each braking member 28 extending inwardlywithin the frame 15 toward the path P and provided with an angle portion29 which extends below the lower surface of metal forming assembly 12.Each braking member 28 is urged upwardly toward a substantiallyhorizontal position by a spring 30. The braking members 28 serve to slowdown the movement of the metal forming assembly 12 as it approaches eachend of the frame 15 to prevent injury to the cylinders '20 and 24.

Metal forming assembly The metal forming assembly 12 is carried by thecarriage rails 19 of the traversing mechanism 14. The metal formingassembly 12 includes a roll-type metal forming machine 31 which isconventional in construction and which forms various types of flangesand locking grooves in sheet metal work. Such a machine is manufacturedby The Lockformer Co., 4615 W. Roosevelt Road, Chicago, 111. 60650. Itis to be understood, however, that different type forming machines maybe used in the metal forming assembly '12. The particular metal formingmachine 31 shown includes a plurality of forming rolls (not shown)mounted in the roll housing 32 on top of the machine which engage theedges of sheet metal and roll the same into the desired configuration.Normally the rolls engage the metal and feed the metal with respect tothe machine, however, the metal is stationary in this application andthe rolls in the housing 32 engage the metal and propel the metalforming machine 31 along the carriage rails 19. The machine 31 ismounted on casters 34 which support the machine on the rails 19 andallow the machine to be easily rolled back and forth along the carriagerails 19.

Added to this conventional metal forming machine 31 is an extensiontable 35 which is in the plane of the table 36 of the forming machine 31and which extends just under the path P along which the metal M moveswhen the metal forming assembly 12 is adjacent the starting fluidcylinder 20 as seen in FIG. 1. A pair of guide arms 38 and 39 extendfrom the roll housing 32 along the top of the extension table 35 intothe path P along which the metal M travels. As the metal M moves alongthe path P it is first engaged by the guide arm 38 and held in positionfor forming by the machine 31. As the metal M moves past the machinealong the path P and then back toward the machine along the path P, thetrailing edge of the metal M engages the guide arm 39 and positions itproperly for engagement by the rolls of the forming machine 31. Theextension table 35 serves to support the metal M prior to engagement bythe machine 31.

A by-pass extension table 40 is provided at the end of the machine 31opposite the table 35 and in the same plane therewith. The table 40supports the metal M when the machine 31 has moved to the far end of thetraversing mechanism 14 and the metal M is moved from the infeedtransfer table to the discharge transfer table 11. The table 40 definesopenings 41 therethrough through which by-pass rolls 42 extend to powerthe metal M from the table 10 to the table 11. The rolls 42 are drivenby a motor 44 connected to the rolls 42 by a belt drive 45. The rolls 42are driven so that metal M will be moved across the table 40 from theright to the left as seen in FIG. 1. A set of freely rotatable hold-downrolls 46 are V 21 positioned above the table 40 over the rolls 42 tomain tain driving contact between the metal M and rolls 42. The rolls 46are urged toward rolls 42 by springs 48.

Infeed transfer table The infeed transfer table 10 is positionedadjacent the traversing mechanism 14 as seen in FIG. 1 on the right sidethereof. It is substantially centered along the length of the mechanism14 perpendicular thereto and the path of travel of the assembly 12 is ofsufficient length for the metal to clear the roll housing 32 when theassembly 12 is in its initial position and when the assembly 12 is inits traversed position. The table 10 comprises a frame 49 whichrotatably mounts a plurality of axially aligned, laterally spacedrollers 50 at each end thereof. The rollers 50 mount endless belts 5.1therearound in a position such that the upper flights of the belts 51are in the plane of the extension tables and 40 of the assembly 12. Thebelts 51 are moved continuously in the direction shown by arrows 52 by aconventional drive mechanism 53 (see FIG. 6). The metal M that has beencut to length is fed to the table 10 which in turn moves the metal Mtoward the guide arm 38. The speed of the belts 551 can be varied tomove the metal M toward the guide arm 38 at the desired speed.

Positioned along that edge of the frame 49 facing the assembly 12 is apair of laterally spaced hold-down fluid cylinders 54. The piston rods55 of the cylinders 54 extend downwardly and have rubber pads 56 on thedepending end of each. When fluid is supplied to the cylinders 54, therods 55 thereof force the pads 56 down against the frame 49. If themetal M is between the frame 10 and pads 56, it will be locked inposition, but if the metal M is not between the frame 10 and pads '56,the pads 56 will block the movement of metal M into the space Dischargetransfer table The discharge transfer table 11 is positioned adjacentthe left side of the traversing mechanism 14 as seen in FIG. 1. It issubstantially centered along the length of the mechanism 14 in alignmentwith the table 10 so that the table 10 and table 11 move each piece ofmetal M along the common path P. The discharge transfer table 11includes a frame 58 having legs 59 as seen in FIG. 3 which support thesame. A pair of spaced parallel side members 60 extend between legs 59and a pair of spaced parallel end members 61 join the legs 59 and sidemembers 60 to define an open rectangular shape. Spaced intermediatemembers 62 connect the end members 61 and are parallel to side members60.

Rotatably mounted between the side and intermediate members 60 and 62are a plurality of rolls 64 which are spaced back from the entry end ofthe frame 58 and are mounted on a common shaft 65. The shaft 65 isjournalled in bearing blocks 66 in FIGS. 3 and 4 carried by intermediatemembers 62. A plurality of rolls 68 are rotatably operation will mountedbetween the side and intermediate members 60' and 62 as seen in FIGS. 2and 4 on a common shaft 69 journalled in bearing blocks 70 adjacent theexit end of frame 58. The rolls 64 and 68 mount endless return belts 71therebetween. The shaft 65 is driven by a conventional driving mechanism72 so that the upper flights of belts 71 lie in the same plane as theupper flights of the belts 51 and move toward the assembly 12 as shownby arrows 73 in FIGS. 1 and 2.

A plurality of driving discharge rolls 74 are rotatably carried betweenthe rolls 64 and spaced adjacent the entry end of the frame 58. Therolls 74'are mounted on a common shaft 75 parallel to the shaft 65 andspaced therefrom. The shaft 75 is journalled in bearing blocks 76mounted on pivot links 78 which are pivotally mounted on the shaft 65. Aspur gear 79 is mounted on shaft 65 and a pinion 80 is mounted on shaft75 in mesh with gear 79. Therefore, it will be seen that the gear 79will drive shaft 75 as shaft 65 is rotated by mechanism 72. The links 78can be pivoted about shaft 65 to vary the vertical position of shaft 75as seen in FIG. 4.

A plurality of driven discharge rolls 81 are mounted on a common shaft82 inwardly of the exit end of the frame 58. The shaft 82 is journalledin bearings 84 carried by side members 60 and positions the uppermostsurface of the rolls 81 in substantially the same horizontal plane asthe uppermost surface of rolls 68. The rolls 74 and 81 mount endlessbelts 85 therebetween so that as the rolls 74 are moved up and down bypivoting the links 78, the upper flights of belts 85 will move above andbelow the upper flights of the belts 71 as seen in FIGS. 3 and 4. Thegear 79 and pinion 80 serve to move the belts 85 away from the assembly12 as shown by arrows 86 in FIGS. 1 and 2. The gear 79 and pinion 80 areso constructed that the belts 85 are moved faster than the belts 71 toinsure that the metal M will clear the assembly 12. The arrangementshown moves the belts 85 three times faster than belts 71.

A vertically movable support member 88 is positioned under the upperflight of each of the belts 85. The members 88 are carried by atransversely extending sub-carriage 89 at each end thereof. Each of thesub-carriages 89 is carried by the piston rods 90 of a pair of spacedfluid cylinders 91. The fluid cylinders 91 are mounted on carriage beams92 extending between legs 59 of frame 58 below the side, end andintermediate members 60, 61 and 62. When the piston rods 90 areextended, the upper flights of belts 85 will be positioned above theplane of the upper flights of belts 71 and when they are retracted, theupper flights of belts 85 will be below the plane of the upper flightsof belts 71. In this manner, the belts 85 are used to discharge theformed metal M and the belts 71 are used to return the partially formedmetal M back toward the guide arm 39.

The extending end of each link 78 is pinned to the piston rod 94 of afluid cylinder 95 carried by the carriage beams 92. When the piston rods94 are extended, the uppermost surfaces of rolls 74 are above theuppermost surfaces of rolls 64 so that the belts 85 are also above thebelts 71 at the right ends thereof as seen in FIG. 3. This also servesto reduce the tension in the belts 85 so that the members 88 can beraised by cylinders 91. When the piston rods 94 are retracted, the rightends of belts 85 are below the belts 71 as seen in FIG. 4. The operationof these various components is set forth hereinafter.

A pair of hold-down fluid cylinders 96 are carried by the frame 58adjacent the assembly 12 and correspond in construction and function tothe hold-down cylinders 54 of the table Each cylinder 96 has a pistonrod 98 with a pad 99 on the depending end thereof. As the piston rods 98are extended, the pads 99 will move toward end member 61 as seen in FIG.3 to clamp metal M therebetween or prevent metal M from moving back intothe path of the assembly 12.

CONTROL CIRCUIT The electrical control circuit U is shown schematicallyin FIG. 6 and the various switches as well as their function are listedin the table below:

Switch: Function SW-l Closed when leading edge of metal in firstpredetermined position and serves, in conjunction with SW-Z to move theforming machine into contact with the metal.

SW-2 Closed when trailing edge of metal in second predetermined positionand serves, in conjunction with SW-l, to move the forming machine intocontact with the metal.

SW-3 Opened when metal is crossing by-pass extension table and serves,in conjunction with SW-4 and SW-9, to prevent return of forming machinewhen metal interferes with its movement.

SW-4 Opened when metal on infeed table interferes with return of formingmachine and serves, in conjunction with SW-3 and SW-9, to prevent returnof forming machine when metal interferes with its movement.

SW-5 Closed when forming machine has passed across metal to raisedischarge belts into engagement with metal on discharge table.

SW-6 Closed as forming machine starts across metal to activate cam tocontrol SW-9.

SW-7 Closed as forming machine moves across traversing mechanism andactivates hold-down fluid cylinders on infeed and dicharge transfertables.

SW8 Closed as forming machine moves across traversing mechanism andactivates hold-down fluid cylinders on infeed and discharge transfertables.

SW-9 Closed when forming machine in traversed position and serves, inconjunction with SW-3 and SW-4 to return forming machine to its initialposition.

SW-10 Manually closed to by-pass SW-2 to start operation with one pieceof metal.

The control circuit U includes a hot wire 100 and a ground wire 101.Switches SW-l, SW-2, SW- SW-7, SW-8, and SW-9 are normally open camoperated switches of conventional construction while switches SW-3 andSW-4 are normally closed cam operated switches. Switch SW-6 is a twoposition toggle switch of conventional construction and will remain ineither position. Switch SW-10 is a normally open push button switch ofconventional construction.

Switches SW-1 and SW-Z in series with solenoid SOL-1 connect wires 100and 101. Switch SW-10 is connected across switch SW-2 in paralleltherewith. Switches SW-3, SW4, and SW-9 in series with solenoid SOL-2connect wires 100 and 101. Switches SW-7 and SW-8 in parallel with eachother and in series with solenoid SOL-3 also connect wires 100 and 101.Switch SW-S in series with solenoid SOL-4 connects wires 100 and 101while switch SW-6 in series with solenoid SOL-5 connects the wires 100and 101 also. The drive motor of mechanism 53 is connected between wires100 and 101 in series with a variable speed controller 102, and thedrive motor of mechanism 72 is connected between wires 100 and 10 1 inseries with a variable speed controller 104.

The switch SW-l is located on the extension table 35 in the guide arm 38so that it will be activated when the metal M engages the arm 38. Theswitch SW-2 is located on the extension table 35 in the guide arm 39 sothat when the metal M engages the guide arm 39, the switch SW-2 will beactivated. The switch SW-3 is located in the by-pass extension table 40so that it will be activated when the metal is on the extension table40. The switch SW-4 is located on the exit end of the infeed transfertable 10 so that it will be activated by the metal M while it isprotruding into the path of the assembly 12.

The switch SW-S is located on the entry end of the discharge table 11 sothat it is activated by the assembly 12 when the assembly has traversedthe mechanism 14 and cleared the metal M. The switch SW-6 is located onthe side of the assembly 12, and is closed as the assembly 12 traversesthe mechanism 14 and is opened when the assembly 12 is returned. SwitchSW-7 is located on the exit end of the infeed transfer table 10 adjacentthe assembly 12 in its initial position and is activated by a earn 105as seen in FIG. 1 when the assembly 12 is starting its traversingmovement or is completing its return movement. The switch SW-8 islocated on the exit end of the infeed transfer table in alignment withswitch SW-7 but on the opposite side of the table '10 and is activatedby cam 105'as the assembly 12 is completing its traversing movement andis starting its return movement.

Switch SW-9 is located on the entry end of the discharge transfer table11 and is activated by an appropriate cam (not shown) on the assembly 12as it reaches the traversed position. Switch SW-10 is located on anappropriate control panel (not shown) and is manually activated.

FIG. 6 is a schematic diagram of the fluid control circuit H. Thecircuit H shows the cylinders 54 and 96 in parallel connected to themanifold M built into the frames 49 and 58 through valve V3 activated bysolenoid SOL-3. Cylinders 91 and 95 are in parallel with each other andconnected to the manifold M through valve V4 activated by solenoidSOL-4. Cylinder 20 is connected to manifold M through valve V1 activatedby solenoid SOL1 and cylinder 24 is connected to manifold M throughvalve V2 activated by solenoid SOL-2. The cylinders 54, 91, 94 and 96are of the conventional retracting type when pressure is not appliedthereto. It is to be understood that different types of components maybe used in the circuits U and H from those shown without departing fromthe scope of the invention.

' OPERATION In operation, it will be seen that the invention is set upfor operation by appropriately adjusting the speed of the belts 51, 71and 85 by manipulating the controllers 102 and 104. A piece of sheetmetal M is cut to length and deposited on the belts 51 of the infeedtransfer table 10. The belts 51 move the piece of metal M along the pathP until the leading edge of the metal M engages the guide arm 38. Themetal M is in its first predetermined position and has closed switchSW-l and opened switch SW4. The switch SW-10 is closed manually to shortout switch SW2. This energizes solenoid SOL-1 to activate valve V1 andsupply fluid from a pressure source (not shown) through manifold M tocylinder 20 and extends piston rod 21. This moves the assembly 12sufficiently far toward the metal M for the rolls in the housing 32 toengage the leading edge of the metal M.

Since the machine 31 is constantly energized, the rolls in housing 32engage the metal M and move the machine 31 across the leading edge ofthe metal while forming the same. At about the time the rolls engage themetalM, the cam 105 closes switch SW-7 to energize solenoid SOL-3. Thiscauses valve V3 to admit fluid under pressure from manifold M tocylinders 54 and 96 to extend piston rods 55 and 98 to clamp the metal Min position.

As the machine 31 continues to move across the metal M by the rolls inhousing 32, the cam 105 eventually engages switch SW-8 to maintain thepiston rods 55 and 98 extended. The cam 105 may be so constructed thatswitch SW-7 is opened momentarily before switch SW-8 is closed. Thisallows the metal M to be released momentarily so that the rolls in thehousing 32 may realign the metal M with respect thereto. The alignmentfunction is inherent in the operation of the machine 31.

When the rolls in housing 32 clear the leading edge of the metal M,there is enough momentum in the machine 31 to carry it to its fulltraversed position to be engaged by braking members 28 and its movementarrested. In this position, the metal M can pass the roll housing 30across the by-pass extension table 40. As the assembly 12 reaches itstraversed position, cam 105 releases switch SW-8 thereby allowing it toopen and release the metal M. Switch SW-6 has already been tripped toits closed position by an appropriate cam (not shown) so that solenoidSOL- is energized and the cam (not shown) that operates switch SW-9 isextended to close switch SW-9 when the assembly 12 is in its traversedposition. Switch SW-S is also closed by an appropriate cam (not shown)on the assembly 12 when in its traversed position. This energizes valveV4 to extend piston rods and 94 of cylinders 91 and 95 and raisedischarge belts 85 abov return belts 71.

The piece of metal M that has its leading edge formed is then movedacross table 40 by belts 51 of the infeed transfer table 10 and thecontinuously operating rolls 42 in table 40 and onto the raised belts 85of the discharge transfer table 11. The belts 85 then move the metal Mwith its leading edge formed along the path P away from the assembly 12.

As soon as the metal M clears switches SW-3 and SW-4, solenoid SOL-2 isenergized as switches SW-3 and SW-4 close since switch SW-9 is alreadyclosed. This causes valve V2 to extend piston rod 25 of cylinder 24 toreturn the assembly 12 back to its original position. As soon as theassembly 12 starts its return movement, switches SW-S are opened tolower the discharge belts 85 below the belts 71 so that the metal Mhaving its leading edge formed is dropped on belts 71 and starts backtoward the assembly 12. Switch SW-9 is also opened when the assembly 12leaves its traversed position to remove the pressure from cylinder 24.Switches SW-7 and SW-8 are closed by cam as the assembly 12 is returningin reverse order from that set forth on the traversing movement so thatthe pads 56 and 99 prevent metal M from entering into interference withthe return of assembly 12. As the assembly 12 approaches its initialposition, the switch SW-G is tripped to its open position to retract itsassociated cam (not shown).

While the assembly 12 is returning, another piece of metaal M is beingmoved along the path P by the infeed transfer table 10 and the piece ofmetal M on the discharge transfer table is being returned along the pathP toward assembly 12. When the assembly 12 is returned to its initialposition, cam 105 clears switches SW-7 and SW-8 so that piston rods 55and 98 of hold down cylinders 54 and 96 are retracted. This allows thetable 10 to move the leading edge of the second piece of metal M againstthe guide arm 38 to its first predetermined position and the table 11 tomove the trailing edge of the first piece of metal M back against theguide arm 39 to its second predetermined position. These positions areshown by dotted lines in FIG. 2. In these positions switch SW-l isclosed by the leading edge of the second piece of metal M and the switchSW-2 is closed by the trailing edge of the first piece of metal M. Thisactivates cylinder 20' to move the rolls in housing 32 into engagementwith the leading edge of the second piece of metal and the trailing edgeof the first piece of metal.

The rolls in housing 32 move the assembly 12 to its traversed positionas set forth above to form both the leading and trailing edges. Thistime, however, the cylinders 96 clamp the first piece of metal M inposition while the cylinders 54 clamp the second piece of metal M inposition. At the end of the traverse movement of the assembly 12, thedischarge belts are raised and moves the first piece of metal M from thetable 11 and moves the second piece of metal M into the position of thefirst piece on the table 11. The operation continues as more pieces ofmetal are fed to table 10.

The speed of belts 51, 71 and 85 are adjusted to present new pieces ofmetal to the assembly 12 at the appropriate intervals and to dischargeeach piece of metal having both leading and trailing edges formed fromthe table 11 but keep the metal with only the leading edge formed on thetable 11.

It is to be understood that the use of modifications, substitutions, andequivalents may be used without departing from the scope of thisinvention.

I claim:

1. Apparatus for successively forming lengths of sheet metal comprising:

a transfer mechanism including first means for successively moving eachlength of the sheet in a first direction along a prescribed path to afirst predetermined position, and second means for successively andselectively moving each length of the sheet metal in said firstdirection away from said first predetermined position and forselectively and successively moving each length of the sheet metal in asecond direction opposite said first direction to a second predeterminedposition;

hold-down means for selectively maintaining each length of the metal insaid first predetermined position and in said second predeterminedposition;

a metal forming mechanism constructed and arranged to form the edges ofeach length of the sheet metal; and,

traversing means for moving said metal forming mechanism across saidprescribed path when one of the lengths of sheet metal is in said firstpredetermined position and in said second predetermined position to formthe edges thereof.

2. Apparatus for successively forming lengths of sheet metal comprising:

transfer means for successively moving each length of the sheet metalalong a prescribed path to a first predetermined position and a secondpredetermined position wherein said transfer means includes:

an infeed transfer table for successively moving the lengths along saidprescribed path to said first predetermined position;

a discharge transfer table for receiving the lengths of sheet metal, andfor selectively moving the lengths along said path in said firstdirection away from said second predetermined position and in a seconddirection opposite to said first position to said second predeterminedposition; and

by-pass table means for transferring the lengths of metal along saidprescribed path in said first direction from said infeed transfer tableto said discharge transfer table;

hold-down means for selectively maintaining each length of the metal insaid first predetermined posi tion and in said second predeterminedposition;

a metal forming mechanism constructed and arranged to form the edges ofeach length of the sheet metal; and,

traversing means for moving said metal forming mechanism across saidprescribed path when one of the lengths of sheet metal is in said firstpredetermined position and in said second predetermined position to formthe edges thereof.

3. The apparatus of claim 2 further including control means operativelyconnected to said transfer means, said hold-down means, said metalforming mechanism, and said traversing means for causing each length ofsheet metal to be moved by said infeed transfer table to said firstpredetermined position, said hold-down means to engage and fix thelength of sheet metal in said first predetermined position, saidtraversing means to move said metal forming mechanism across the leadingedge of the length of sheet metal in said first predetermined positionto form same, said hold-down means to release the length of sheet metal,said by-pass table means to move said length of sheet metal from saidinfeed transfer table to said discharge transfer table after said metalforming mechanism has passed the leading edge of the length of sheetmetal, said discharge transfer table to move the length of sheet metalaway from said metal forming mechanism, said traversing means to movesaid metal forming machine back across said prescribed path to itsinitial position, said discharge transfer table to move the length ofsheet metal along said prescribed path in said second direction to saidsecond predetermined position while said infeed transfer table is movinganother length of sheet metal to said first predetermined position, saidhold-down means to fix the length of sheet metal with the leading edgeformed in said second predetermined position while the other length ofsheet metal is fixed in said first predetermined position, and saidtraversing means to move said metal forming machine across the trailingedge of the length of sheet metal in said second predetermined positionwhile said metal forming machine is moved across the leading edge of thelength of sheet metal in said first predetermined position.

4. The apparatus of claim 3 wherein said discharge transfer tableincludes a first plurality of belts extending parallel to saidprescribed path, a second lurality of belts extending parallel to saidprescribed path and interposed between said first plurality of belts,means for moving said first plurality of belts in said first directionand said second plurality of belts in said second direction, andpositioning means for selectively positioning said first plurality ofbelts above and below said second plurality of belts.

5. The apparatus of claim 4 wherein said metal forming mechanismincludes a conventional sheet metal roll forming machine, a first guidearm aligned with said roll forming machine to stop said lengths of sheetmetal at said first predetedmined position in position for the leadingedge thereof to be engaged by said roll forming machine, and a secondguide arm spaced from said first guide arm aligned with said rollforming machine to stop said lengths of sheet metal at said secondpredetermined position in position for the trailing edge thereof to beengaged by said roll forming machine.

References Cited UNITED STATES PATENTS 3,476,000 11/1969 Wheeler 836142,627,890 2/1953 Lloyd et al. 72-27 2,792,890 5/1957 Dyken 836l4 CHARLESW. LANHAM, Primary Examiner M. J. KEENAN, Assistant Examiner U.S. Cl.X.R.

